Instructions:

Cut the chicken breasts into bite-sized pieces. Heat the oil and cook the onion gently for 5-6 minutes. Add the chicken, sprinkle it with tarragon and pepper, and add 0.5 l water. Cook for about 40-45 minutes until the chicken is tender.Add flour, 1 l water, and cook for 1-2 minutes stirring constantly. Add white wine, increase heat to high and cook until liquid is almost evaporated, stirring continuously.Slice the vegetables and add them to the soup. Add lemon juice and mustard. Reduce the heat to a simmer, cover the pot and cook for 10 minutes.Mix ½ cup of heavy cream with ½ cup of sour cream until thoroughly combined. Add the mixture and blend the soup until it is smooth.Sprinkle a little tarragon on top.